Endocrine - 08 - Pathology of Thyroid

forms from a persistant thyroglossal duct

painless neck lump that can get infected, or cause breathing issues

will move upward with protrusion of tongue

can have ecoptic thyroid tissue

forms from a persistant thyroglossal duct

painless neck lump that can get infected, or cause breathing issues

will move upward with protrusion of tongue

can have ecoptic thyroid tissue

grave's disease

grave's disease

increased T3 and T4

increased uptake of radioactive iodine

see in grave's disease

hashimoto's thyroiditis (in areas where nutritional iodine is not scarce)

worldwide most common is iodine deficiency

increased T3 and T4

increased uptake of radioactive iodine

see in grave's disease

hashimoto's thyroiditis

increased TSH

decreased TSH

decreased brain maturation - stunted growth

often associated with ACTH deficiency

replacement of thyroid hormone can cause cortical insufficiency crisis

most common cause of goitrous hypothyroidism in places with sufficient iodine (in the US)

HLA-DR5 associated

can begin with hyperthroidism (hashitoxicosis)

antigent specific T supressor cells - antibodies against thyroid component

see thyroid fibrosis, enlargement (goiter), tan/orange, fleshy lobules

oncocytes/hurthle cells - epithelial cells filled with eosinophilic granules

increased incidence of lymphoma

viral etiology

pronounced neck pain, painful tender enlargement of thyroid gland

capsule may be involved, may see irregular involvement, adherence to surrounding tissue, brown and rubbery

increased ESR

self limited

associated with hyperthyroidism - destruction of follicles release thyroid hormone

if enough damage, progresses to hypothyroidism

variant of subacute granulomatous thyroiditis

most common after pregnancy

painless

often appears normal - escapes detection

unknown cause

rare, chronic thyroiditis

fibrosing reaction destroys the gland

fibrosis expands beyound the capsule - becomes fixed, hard, nodular

looks like a malignancy

see lots of unorganized fibrosis within gland

can -> hypothyroidism, hoarse voice, stridor

see goiter, bug eyed, hyperactive thyroid

HLA-DR3

associated with other autoimmune disease

ophthalmopathy is key feature - edematous inflammation - fibroblasts around the eyes have TSH like receptors

IgG antibodies against TSH receptor

see large folicles, and pseudopapilla due to overlapping folicles

endemic - often due to lack of iodine, or possible too much goitrogens

nonendemic - less common, occurs at puberty, unknown cause

patient usually reach euthyroid state, rarely hypothyroid

treat with iodine often

all long standing simple goiters become multinodular

due to unevek accumulation of colloid, rupture of these follicles -> scarring -> nodules

euthyroid

often mistaken for malignancy

older age

see variations of sizes of follicles under microscopy

adenoma

but the younger the patient the increased suspicion for carcinoma

solitary discrete small nodule

may cause pressure symptoms, may become painfully large if hemorrhage, may be hyperfunctioning -> thyrotoxicosis

does not become malignant

diagnosis requires:
fibrous encapsultation

clear demarkation between nodule and outside thyroid

compression of surrounding thyroid

lack of multinodularity

multinodular goiter - don't see mass effect of nodules (no compression of thyroid parenchyma)

adenomas are usually singular

most common form of thyroid cancer

indolent course

microscopy shows true papilla with fibrovascular core, psommoma body, orphan annie nuclei

propensity to metastasize to LN

formalin artifact - chromatin condenses along nuclear membrane - leaves a round circle appearance

no papillary morphology

no ground glass nuclei/orphan annie eye

no psammoma bodies

hematogenous metastasis to distance sites (does not involve LN usually)

agressive

amyloid stroma

calcitonin secreting

MEN 2a, 2b syndrome association

genetic defect in Chr 10

most malignant neoplasm in man

old age 7-8th decades of life

lots of chromosome problems